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