One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,8)(3,6,4,7)(11,18)(15,22)(19,23)(20,24)(25,26,30,34)(27,33,38,31)(28,32,39,29)(35,40,37,36)(1,2)(3,6)(4,7)(5,8)(9,10,14,17)(11,15,18,22)(12,13,16,21)(19,20,23,24)(25,27)(26,31)(28,37)(29,36)(30,38)(32,40)(33,34)(35,39)(9,11)(10,15)(12,19)(13,20)(14,18)(16,23)(17,22)(21,24)(25,28)(26,32)(27,35)(29,34)(30,39)(31,36)(33,40)(37,38) involution — undirected(1,3,5,4)(2,6,8,7)(9,11)(10,15)(12,19)(13,20)(14,18)(16,23)(17,22)(21,24)(25,29,30,32)(26,28,34,39)(27,36,38,40)(31,37,33,35)(1,3,5,4)(2,6,8,7)(9,12)(10,13)(11,19)(14,16)(15,20)(17,21)(18,23)(22,24)(25,28)(26,32)(27,37)(29,34)(30,39)(31,40)(33,36)(35,38)(1,4,5,3)(2,7,8,6)(9,13)(10,16)(11,20)(12,17)(14,21)(15,23)(18,24)(19,22)(25,27)(26,33)(28,35)(29,36)(30,38)(31,34)(32,40)(37,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.