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