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