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