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