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