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