One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,6)(5,8)(9,10,14,15)(11,16,19,22)(12,17,18,13)(20,23,24,21)(25,26,30,33)(27,28,31,34)(29,32,38,40)(35,36,39,37)(1,3,5,4)(2,6,8,7)(10,15)(11,19)(12,18)(21,23)(25,27)(26,28)(29,35)(30,31)(32,36)(33,34)(37,40)(38,39)(1,3,5,4)(2,7,8,6)(10,15)(11,19)(12,18)(21,23)(27,31)(28,34)(35,39)(36,37)(1,2)(3,7)(4,6)(5,8)(9,11)(10,16)(12,20)(13,21)(14,19)(15,22)(17,23)(18,24)(25,26)(27,34)(28,31)(29,32)(30,33)(35,37)(36,39)(38,40) involution — undirected(1,2)(3,6)(4,7)(5,8)(9,12)(10,17)(11,20)(13,15)(14,18)(16,23)(19,24)(21,22)(25,28,30,34)(26,31,33,27)(29,37,38,36)(32,35,40,39)(1,4,5,3)(2,6,8,7)(9,13,14,17)(10,18,15,12)(11,21,19,23)(16,24,22,20)(25,29)(26,32)(27,35)(28,36)(30,38)(31,39)(33,40)(34,37)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.