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