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