One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,3,4)(5,6)(7,9)(8,12)(10,11)(13,14,16,18)(15,17,19,20)(21,22,25,23)(24,26,28,27)(5,7)(6,8)(9,11)(10,12)(13,15,16,19)(14,17,18,20)(21,23,25,22)(24,26,28,27)(5,8,10,9)(6,7,11,12)(13,14)(15,17)(16,18)(19,20)(21,24,25,28)(22,26,23,27)(1,2)(3,4)(5,9,10,8)(6,7,11,12)(13,15)(14,17)(16,19)(18,20)(5,7)(6,8)(9,11)(10,12)(13,14)(15,17)(16,18)(19,20) involution — undirectedA 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.