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